ISO 21524:2021
(Main)Fire resistance tests — Elements of building construction — Requirements for active fire curtains
Fire resistance tests — Elements of building construction — Requirements for active fire curtains
This document specifies requirements for the design, testing and classification of active fire curtains, applicable to any material, that are designed to provide fire and smoke resistance. This document gives recommendations for the application, installation and maintenance of active fire curtains. It is also intended to provide guidance and recommendations for designers, specifiers (e.g. architects, fire engineers), authorities having jurisdiction (AHJs), installers and maintainers for the following: a) creating compartmentation; b) creating protected routes for the purpose of means of escape; c) providing protection at the location of non-fire resisting elements (e.g. in front of non-fire-resisting glazing and doorsets) where required for compartmentation or protecting means of escape; d) providing fire- and smoke-resistant active fire curtains in conjunction with non-smoke rated products protecting openings to reduce leakage of smoke. This document does not apply to the following, which are intended for a different use: — barriers made of part of the building’s structure; — theatre/proscenium textile curtains; — smoke barriers according to ISO 21927-1; — door and shutter assemblies according to ISO 3008‑1. NOTE 1 Smoke barriers used solely for smoke control are covered by ISO 21927‑1. Such smoke barriers are not considered to be active fire curtains. NOTE 2 Requirements of fire doors are given in ISO 3008-1. Requirements for leakage are given in ISO 5925‑1 and further information is given in ISO/TR 5925‑2.
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INTERNATIONAL ISO
STANDARD 21524
First edition
2021-07
Fire resistance tests — Elements
of building construction —
Requirements for active fire curtains
Reference number
ISO 21524:2021(E)
©
ISO 2021
---------------------- Page: 1 ----------------------
ISO 21524:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 21524:2021(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 4
5 Requirements . 5
5.1 General . 5
5.2 Side retention . 6
5.3 Additional requirements for multiple active fire curtains . 7
5.3.1 Multiple active fire curtains . 7
5.3.2 Required overlap . 9
5.3.3 Larger than tested . . 9
5.4 Horizontal or angled . 9
5.5 Pass door(s) .11
5.6 Vision panels .12
6 Sampling .13
6.1 Test samples, testing and conformance criteria .13
7 Test methods .14
7.1 General .14
7.2 Durability and force gauge .15
7.3 Reliability and durability.15
7.4 Deployment .15
7.4.1 Response time and velocity .15
7.4.2 Delayed and/or multi-positional deployment .16
7.4.3 Emergency egress control .16
7.4.4 Emergency access control . .16
7.5 Smoke leakage .16
7.5.1 General.16
7.5.2 Total smoke leakage of active fire curtains with smoke-resistance .16
7.6 Fire resistance .16
7.6.1 General.16
7.6.2 Integrity .17
7.6.3 Insulation .17
7.6.4 Radiation (heat flux) .17
7.6.5 Deflection zone .18
7.6.6 Initial deployment .18
7.6.7 Operation following initial deployment — emergency egress .18
7.6.8 Operation following initial deployment — emergency access.18
7.6.9 Delayed and/or multi-positional deployment .18
7.7 Reaction to fire .18
7.8 Ancillary devices.19
7.8.1 General.19
7.8.2 Ancillary devices activation .19
7.8.3 Hold-open devices .19
7.8.4 Fire detection and alarm systems .19
7.8.5 Sensory equipment for obstruction warning .19
7.8.6 Pressure-sensitive protective equipment (PSPE).19
7.8.7 Self-test facility for dwellings .19
8 Marking, labelling and packaging .20
Annex A (normative) General requirements for testing .21
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ISO 21524:2021(E)
Annex B (normative) Order of testing .24
Annex C (normative) Fire-resistance test method .26
Annex D (normative) Overlapping multiple active fire curtains .41
Annex E (normative) Test method for active fire curtains reliability and response time and
the durability of materials .43
Annex F (normative) Test method for reliability of motor operation at elevated temperatures .46
Annex G (normative) Calculation of ambient temperature smoke leakage .52
Annex H (normative) Test method for the durability and reliability of alternative or
additional motors .55
Annex I (normative) Test method for ancillary and optional equipment .58
Annex J (normative) Test method for durability and force gauge .62
Annex K (informative) Typical product performance summary .65
Annex L (normative) System design .67
Annex M (informative) Installation.79
Annex N (informative) Commissioning .83
Annex O (informative) Inspection, testing and maintenance .86
Annex P (informative) Typical approving authority pre-installation checklist .88
Annex Q (informative) An engineered approach to using radiative heat flux for tenable
conditions for single-level horizontal routes .89
Annex R (informative) Yarns and fabric materials .99
Annex S (informative) Typical installation checklist .100
Annex T (informative) Model installation certificate .103
Annex U (informative) Typical inspection checklist .105
Annex V (informative) Model commissioning certificate.107
Annex W (informative) Model completion certificate .109
Annex X (informative) Model servicing certificate .111
Bibliography .113
iv © ISO 2021 – All rights reserved
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ISO 21524:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 92, Fire safety, Subcommittee SC 2, Fire
containment.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2021 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 21524:2021(E)
Introduction
As fire-separating elements, active fire curtains are intended to provide two main functions:
a) to maintain any compartmentation of buildings needed to limit the spread of fire and smoke; and
b) to allow access to protected escape routes, both vertical and horizontal, without any loss of fire
resistance, and to limit smoke entry into these routes, i.e. protected corridors and protected shafts.
They can also be partially deployed to control the deployment of fire effluent within buildings in the
event of fire, prior to being fully deployed as active fire curtains.
Recommended positions and ratings for fire-separating elements for means of escape purposes are
given in national codes providing either prescriptive or risk-based approaches using the principles of
fire safety engineering.
When used as part of a fire-engineered design solution, active fire curtains can become a critical
element of design. If active fire curtains do not deploy to their operational position, the fire-engineered
design solution is compromised. However, in the event that other fire protection systems or elements
do not function (e.g. due to total power failure), active fire curtains in their fire-operational position
provide fire separation.
Active fire curtains used in life safety and property protection applications can be vertical, horizontal
or angled. Depending on the application, they are at times used to replace fire doors, roller shutters,
non-loadbearing walls, non-loadbearing ceilings, glazed elements, etc. At times, they are also used to
form fire separation, e.g. forming protected routes or lobbies. They provide some of the functionalities
of a fire door, but when used only for fire and smoke leakage, as a fire door, then different requirements
apply. These requirements are given in ISO 3008-1 and ISO 5925-1, and further information is given in
ISO/TR 5925-2. Active fire curtains enable greater widths and deployments using less space than other
traditional methods.
It is essential that any proposed use of active fire curtains be assessed in the context of the building
use and perceived occupancy to ensure that it is ultimately suitable and fit for purpose, taking into
consideration such factors as:
a) fire resistance;
b) reaction to fire;
c) smoke leakage;
d) occupancy type and risk profile;
e) occupancy load;
f) means of escape for egress;
g) ingress for fire and rescue service;
h) life safety and property protection objectives.
Some examples of how active fire curtains are deployed are:
a) deploy fully upon receipt of a signal from the fire alarm system;
b) remain retracted when the fire alarm system is activated and only deploy upon receipt of a signal
from a local smoke/heat detector. In these circumstances, the only active fire curtains to deploy
are those where fire or smoke are in the vicinity;
c) remain retracted when the fire alarm system is activated for a predetermined time to allow for
evacuation before deploying fully;
vi © ISO 2021 – All rights reserved
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ISO 21524:2021(E)
d) for vertical installations, move to a given height above finished floor level when the fire alarm
system is activated to contain smoke for a predetermined time before closing fully for fire
separation;
e) for vertical installations, move to a given height above finished floor level when a specific fire alarm
system signal is provided to contain smoke when the fire location is such that active fire curtains
are not required to deploy fully;
f) deploy upon loss of primary and auxiliary power supply.
In fire safety situations, it is often important to establish the heat transfer from one side of the
separating element to the other in order to calculate escape route sizes and safe operating distances.
Traditionally this has been established using insulation and radiation measurements.
NOTE National codes apply to life safety. Higher performance levels are sometimes necessary for certain
applications if property protection is required.
© ISO 2021 – All rights reserved vii
---------------------- Page: 7 ----------------------
INTERNATIONAL STANDARD ISO 21524:2021(E)
Fire resistance tests — Elements of building construction
— Requirements for active fire curtains
1 Scope
This document specifies requirements for the design, testing and classification of active fire curtains,
applicable to any material, that are designed to provide fire and smoke resistance.
This document gives recommendations for the application, installation and maintenance of active fire
curtains. It is also intended to provide guidance and recommendations for designers, specifiers (e.g.
architects, fire engineers), authorities having jurisdiction (AHJs), installers and maintainers for the
following:
a) creating compartmentation;
b) creating protected routes for the purpose of means of escape;
c) providing protection at the location of non-fire resisting elements (e.g. in front of non-fire-resisting
glazing and doorsets) where required for compartmentation or protecting means of escape;
d) providing fire- and smoke-resistant active fire curtains in conjunction with non-smoke rated
products protecting openings to reduce leakage of smoke.
This document does not apply to the following, which are intended for a different use:
— barriers made of part of the building’s structure;
— theatre/proscenium textile curtains;
— smoke barriers according to ISO 21927-1;
— door and shutter assemblies according to ISO 3008-1.
NOTE 1 Smoke barriers used solely for smoke control are covered by ISO 21927-1. Such smoke barriers are not
considered to be active fire curtains.
NOTE 2 Requirements of fire doors are given in ISO 3008-1. Requirements for leakage are given in ISO 5925-1
and further information is given in ISO/TR 5925-2.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 834-1, Fire-resistance tests — Elements of building construction — Part 1: General requirements
ISO 1182, Reaction to fire tests for products — Non-combustibility test
ISO 1716, Reaction to fire tests for products — Determination of the gross heat of combustion (calorific
value)
ISO 3009, Fire-resistance tests — Elements of building construction — Glazed elements
ISO 5925-1, Fire tests — Smoke-control door and shutter assemblies — Part 1: Ambient- and medium-
temperature leakage tests
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ISO 21524:2021(E)
ISO 9705-1, Reaction to fire tests — Room corner test for wall and ceiling lining products — Part 1: Test
method for a small room configuration
ISO 11925-2, Reaction to fire tests — Ignitability of products subjected to direct impingement of flame —
Part 2: Single-flame source test
ISO 13943, Fire safety — Vocabulary
ISO 21927-10, Smoke and heat control systems — Part 10: Specification for power output devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 834-1 and ISO 13943 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
active fire curtain
curtain, manufactured from flexible materials, not hinged or pivoted, provided for the passage of
persons, air and objects, which, together with its frame as installed in a building, is intended (when
closed) to resist the passage of fire
3.2
compartmentation
process of separating a building or part of a building into one or more rooms, spaces or storeys, with
the intention of preventing the spread of fire to or from another part of the same building or adjoining
building
Note 1 to entry: Compartmentation is mainly implemented to assist the fire and rescue services by confining
the fire within a fire-resisting enclosure. In some instances, it is employed to assist means of escape in buildings
where evacuation might be delayed (e.g. where phased evacuation policy has been applied in premises such as
hospitals and care homes) or where a policy of non-evacuation (e.g. “defend in place” or “stay put strategy”) is
employed, as in blocks of flats.
Note 2 to entry: Fire enclosures specifically for the purpose of means of escape, such as lobby protection to
stairways and enclosure of special risks, are not regarded as compartments and may employ passive smoke
separation measures.
3.3
competent person
individual suitably trained and qualified by knowledge and practical experience and provided with the
necessary instructions to enable the required task(s) to be carried out correctly
3.4
deployment
movement of an active fire curtain from its retracted position to its fire-operational position
3.5
dwelling
unit of residential accommodation occupied (whether or not as a sole or main residence):
a) by a single person or by people living together as a family; or
b) by not more than six residents living together as a single household, including a household where
care is provided for residents
2 © ISO 2021 – All rights reserved
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ISO 21524:2021(E)
3.6
fire effluent
all gases and aerosols, including suspended particles, created by combustion or pyrolysis and emitted
to the environment
[SOURCE: ISO 26367-1:2019, 3.6, modified — Notes to entry removed.]
3.7
fire-operational position
final configuration of an active fire curtain specified by its designer to achieve and be sustained in the
ultimate fire condition of the design
3.8
fire separation
method of providing an element that is intended for use in maintaining separation between two adjacent
areas of a building in the event of a fire to form protected routes and/or compartmentation
3.9
fire strategy
safety design for a particular building determined by prescriptive codes, fire safety engineering or fire
risk assessment
3.10
fit for purpose
ability of a product, process or service to serve a defined purpose under specific conditions
3.11
gravity fail safe
ability of an active fire curtain to move to its fire-operational position in a safe and controlled manner
to facilitate fire separation when all consumable primary and auxiliary power supplies are removed, in
the event of wiring or system corruption, open or short circuit, or any combination thereof
3.12
integrity
ability of a separating element, when exposed to fire on one side, to prevent the passage of flames and
hot gases or occurrence of flames on the unexposed side, for a stated period of time in a standard fire
resistance test
[SOURCE: ISO 22899-1:2007, 3.9]
3.13
hold-open device
element of the hold-open system that allows a gravity fail safe active fire curtain to remain open either
at a pre-set or chosen position until released
3.14
life safety
application of the active fire curtain in its fire-operational position assisting in the protection of the
means of escape and access for the fire and rescue service
3.15
material
fabric
product made from fibres
Note 1 to entry: Within the context of this document, "material" is understood to conform to one of the following
tests:
Note 2 to entry: a) Non-combustible test (ISO 1182).
Note 3 to entry: b) Limited combustibility test (ISO 1716).
© ISO 2021 – All rights reserved 3
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ISO 21524:2021(E)
Note 4 to entry: Within the context of this document, "material" is understood to require the following tests:
Note 5 to entry: a) Room corner test for wall and ceiling linings (ISO/TR 9705-2).
Note 6 to entry: b) Ignitability of products when subjected to direct impingement of flame test (ISO 11925-2).
3.16
means of escape
means whereby a safe route (or routes) in the event of fire is (or are) provided for persons to travel from
any point in a building to a place of ultimate safety
3.17
multi-positional deployment
staged deployment of active fire curtain to provide initial smoke separation prior to full fire separation
3.18
property protection
application of the active fire curtain in its fire-operational condition to protect a building’s contents
and structure
3.19
side retention
retention device which links the active fire curtain fabri
...
INTERNATIONAL ISO
STANDARD 21524
First edition
Fire resistance tests — Elements
of building construction —
Requirements for active fire curtains
PROOF/ÉPREUVE
Reference number
ISO 21524:2021(E)
©
ISO 2021
---------------------- Page: 1 ----------------------
ISO 21524:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii PROOF/ÉPREUVE © ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 21524:2021(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 4
5 Requirements . 5
5.1 General . 5
5.2 Side retention . 6
5.3 Additional requirements for multiple active fire curtains . 6
5.3.1 Multiple active fire curtains . 6
5.3.2 Required overlap . 8
5.3.3 Larger than tested . . 8
5.4 Horizontal or angled . 8
5.5 Pass door(s) .10
5.6 Vision panels .11
6 Sampling .12
6.1 Test samples, testing and conformance criteria .12
7 Test methods .13
7.1 General .13
7.2 Durability and force gauge .14
7.3 Reliability and durability.14
7.4 Deployment .14
7.4.1 Response time and velocity .14
7.4.2 Delayed and/or multi-positional deployment .15
7.4.3 Emergency egress control .15
7.4.4 Emergency access control . .15
7.5 Smoke leakage .15
7.5.1 General.15
7.5.2 Total smoke leakage of active fire curtains with smoke-resistance .15
7.6 Fire resistance .16
7.6.1 General.16
7.6.2 Integrity .16
7.6.3 Insulation .16
7.6.4 Radiation (heat flux) .16
7.6.5 Deflection zone .17
7.6.6 Initial deployment .17
7.6.7 Operation following initial deployment — emergency egress .17
7.6.8 Operation following initial deployment — emergency access.17
7.6.9 Delayed and/or multi-positional deployment .17
7.7 Reaction to fire .17
7.8 Ancillary devices.18
7.8.1 General.18
7.8.2 Ancillary devices activation .18
7.8.3 Hold-open devices .18
7.8.4 Fire detection and alarm systems .18
7.8.5 Sensory equipment for obstruction warning .18
7.8.6 Pressure-sensitive protective equipment (PSPE).18
7.8.7 Self-test facility for dwellings .18
8 Marking, labelling and packaging .19
Annex A (normative) General requirements for testing .20
© ISO 2021 – All rights reserved PROOF/ÉPREUVE iii
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ISO 21524:2021(E)
Annex B (normative) Order of testing .23
Annex C (normative) Fire-resistance test method .25
Annex D (normative) Overlapping multiple active fire curtains .40
Annex E (normative) Test method for active fire curtains reliability and response time and
the durability of materials .42
Annex F (normative) Test method for reliability of motor operation at elevated temperatures .45
Annex G (normative) Calculation of ambient temperature smoke leakage .51
Annex H (normative) Test method for the durability and reliability of alternative or
additional motors .54
Annex I (normative) Test method for ancillary and optional equipment .57
Annex J (normative) Test method for durability and force gauge .61
Annex K (informative) Typical product performance summary .64
Annex L (normative) System design .66
Annex M (informative) Installation.78
Annex N (informative) Commissioning .82
Annex O (informative) Inspection, testing and maintenance .85
Annex P (informative) Typical approving authority pre-installation checklist .87
Annex Q (informative) An engineered approach to using radiative heat flux for tenable
conditions for single-level horizontal routes .88
Annex R (informative) Yarns and fabric materials .99
Annex S (informative) Typical installation checklist .100
Annex T (informative) Model installation certificate .103
Annex U (informative) Typical inspection checklist .105
Annex V (informative) Model commissioning certificate.107
Annex W (informative) Model completion certificate .109
Annex X (informative) Model servicing certificate .111
Bibliography .113
iv PROOF/ÉPREUVE © ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 21524:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 92, Fire safety, Subcommittee SC 2, Fire
containment.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2021 – All rights reserved PROOF/ÉPREUVE v
---------------------- Page: 5 ----------------------
ISO 21524:2021(E)
Introduction
As fire-separating elements, active fire curtains are intended to provide two main functions:
a) to maintain any compartmentation of buildings needed to limit the spread of fire and smoke; and
b) to allow access to protected escape routes, both vertical and horizontal, without any loss of fire
resistance, and to limit smoke entry into these routes, i.e. protected corridors and protected shafts.
They can also be partially deployed to control the deployment of fire effluent within buildings in the
event of fire, prior to being fully deployed as active fire curtains.
Recommended positions and ratings for fire-separating elements for means of escape purposes are
given in national codes providing either prescriptive or risk-based approaches using the principles of
fire safety engineering.
When used as part of a fire-engineered design solution, active fire curtains can become a critical
element of design. If active fire curtains do not deploy to their operational position, the fire-engineered
design solution is compromised. However, in the event that other fire protection systems or elements
do not function (e.g. due to total power failure), active fire curtains in their fire-operational position
provide fire separation.
Active fire curtains used in life safety and property protection applications can be vertical, horizontal
or angled. Depending on the application, they are at times used to replace fire doors, roller shutters,
non-loadbearing walls, non-load-bearing ceilings, glazed elements, etc. At times, they are also used to
form fire separation, e.g. forming protected routes or lobbies. They provide some of the functionalities
of a fire door, but when used only for fire and smoke leakage, as a fire door, then different requirements
apply. These requirements are given in ISO 3008-1 and ISO 5925-1, and further information is given in
ISO/TR 5925-2. Active fire curtains enable greater widths and deployments using less space than other
traditional methods.
It is essential that any proposed use of active fire curtains be assessed in the context of the building
use and perceived occupancy to ensure that it is ultimately suitable and fit for purpose, taking into
consideration such factors as:
a) fire resistance;
b) reaction to fire;
c) smoke leakage;
d) occupancy type and risk profile;
e) occupancy load;
f) means of escape for egress;
g) ingress for fire and rescue service;
h) life safety and property protection objectives.
Some examples of how active fire curtains are deployed are:
a) deploy fully upon receipt of a signal from the fire alarm system;
b) remain retracted when the fire alarm system is activated and only deploy upon receipt of a signal
from a local smoke/heat detector. In these circumstances, the only active fire curtains to deploy
are those where fire or smoke are in the vicinity;
c) remain retracted when the fire alarm system is activated for a predetermined time to allow for
evacuation before deploying fully;
vi PROOF/ÉPREUVE © ISO 2021 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 21524:2021(E)
d) for vertical installations, move to a given height above finished floor level when the fire alarm
system is activated to contain smoke for a predetermined time before closing fully for fire
separation;
e) for vertical installations, move to a given height above finished floor level when a specific fire alarm
system signal is provided to contain smoke when the fire location is such that active fire curtains
are not required to deploy fully;
f) deploy upon loss of primary and auxiliary power supply.
In fire safety situations, it is often important to establish the heat transfer from one side of the
separating element to the other in order to calculate escape route sizes and safe operating distances.
Traditionally this has been established using insulation and radiation measurements.
NOTE National codes apply to life safety. Higher performance levels are sometimes necessary for certain
applications if property protection is required.
© ISO 2021 – All rights reserved PROOF/ÉPREUVE vii
---------------------- Page: 7 ----------------------
INTERNATIONAL STANDARD ISO 21524:2021(E)
Fire resistance tests — Elements of building construction
— Requirements for active fire curtains
1 Scope
This document specifies requirements for the design, testing and classification of active fire curtains,
applicable to any material, that are designed to provide fire and smoke resistance.
This document gives recommendations for the application, installation and maintenance of active fire
curtains. It is also intended to provide guidance and recommendations for designers, specifiers (e.g.
architects, fire engineers), Authorities Having Jurisdiction (AHJs), installers and maintainers for the
following:
a) creating compartmentation;
b) creating protected routes for the purpose of means of escape;
c) providing protection at the location of non-fire resisting elements (e.g. in front of non-fire-resisting
glazing and doorsets) where required for compartmentation or protecting means of escape;
d) providing fire- and smoke-resistant active fire curtains in conjunction with non-smoke rated
products protecting openings to reduce leakage of smoke.
This document does not apply to the following, which are intended for a different use:
— barriers made of part of the building’s structure;
— theatre/proscenium textile curtains;
— smoke barriers according to ISO 21927-1;
— doorsets or operable fabric curtains according to ISO 3008-1.
NOTE 1 Smoke barriers, used solely for smoke control, are covered by ISO 21927-1. Such smoke barriers are
not considered to be active fire curtains.
NOTE 2 Requirements of fire doors are given in ISO 3008-1. Requirements for leakage are given in ISO 5925-1
and further information is given in ISO/TR 5925-2.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 834-1, Fire-resistance tests — Elements of building construction — Part 1: General requirements
ISO 1182, Reaction to fire tests for products — Non-combustibility test
ISO 1716, Reaction to fire tests for products — Determination of the gross heat of combustion (calorific
value)
ISO 3009, Fire-resistance tests — Elements of building construction — Glazed elements
ISO 5925-1, Fire tests — Smoke-control door and shutter assemblies — Part 1: Ambient- and medium-
temperature leakage tests
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ISO 9705-1, Reaction to fire tests — Room corner test for wall and ceiling lining products — Part 1: Test
method for a small room configuration
ISO 11925-2, Reaction to fire tests — Ignitability of products subjected to direct impingement of flame —
Part 2: Single-flame source test
ISO 13943, Fire safety — Vocabulary
ISO 21927-10, Smoke and heat control systems — Part 10: Specification for power output devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 834-1 and ISO 13943 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
active fire curtain
curtain, manufactured from flexible materials, not hinged or pivoted, provided for the passage of
persons, air and objects, which, together with its frame as installed in a building, is intended (when
closed) to resist the passage of fire
3.2
compartmentation
process of separating a building or part of a building into one or more rooms, spaces or storeys, with
the intention of preventing the spread of fire to or from another part of the same building or adjoining
building
Note 1 to entry: Compartmentation is mainly implemented to assist the fire and rescue services by confining
the fire within a fire-resisting enclosure. In some instances, it is employed to assist means of escape in buildings
where evacuation might be delayed (e.g. where phased evacuation policy has been applied in premises such as
hospitals and care homes) or where a policy of non-evacuation (e.g. “defend in place” or “stay put strategy”) is
employed, as in blocks of flats.
Note 2 to entry: Fire enclosures specifically for the purpose of means of escape, such as lobby protection to
stairways and enclosure of special risks, are not regarded as compartments and may employ passive smoke
separation measures.
3.3
competent person
individual suitably trained and qualified by knowledge and practical experience and provided with the
necessary instructions to enable the required task(s) to be carried out correctly
3.4
deployment
movement of an active fire curtain from its retracted position to its fire-operational position
3.5
dwelling
unit of residential accommodation occupied (whether or not as a sole or main residence):
a) by a single person or by people living together as a family; or
b) by not more than six residents living together as a single household, including a household where
care is provided for residents
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3.6
fire effluent
all gases and aerosols, including suspended particles, created by combustion or pyrolysis and emitted
to the environment
[SOURCE: ISO 26367-1:2019, 3.6, modified — Notes to entry removed.]
3.7
fire-operational position
final configuration of an active fire curtain specified by its designer to achieve and be sustained in the
ultimate fire condition of the design
3.8
fire separation
method of providing an element that is intended for use in maintaining separation between two adjacent
areas of a building in the event of a fire to form protected routes and/or compartmentation
3.9
fire strategy
safety design for a particular building determined by prescriptive codes, fire safety engineering or fire
risk assessment
3.10
fit for purpose
ability of a product, process or service to serve a defined purpose under specific conditions
3.11
gravity fail safe
ability of an active fire curtain to move to its fire-operational position in a safe and controlled manner
to facilitate fire separation when all consumable primary and auxiliary power supplies are removed, in
the event of wiring or system corruption, open or short circuit, or any combination thereof
3.12
integrity
ability of a separating element, when exposed to fire on one side, to prevent the passage of flames and
hot gases or occurrence of flames on the unexposed side, for a stated period of time in a standard fire
resistance test
[SOURCE: ISO 22899-1:2007, 3.9]
3.13
hold-open device
element of the hold-open system that allows a gravity fail safe active fire curtain to remain open either
at a pre-set or chosen position until released
3.14
life safety
application of the active fire curtain in its fire-operational position assisting in the protection of the
means of escape and access for the fire and rescue service
3.15
material
fabric
product made from fibres
Note 1 to entry: Within the context of this document, "material" is understood to conform to one of the following
tests:
Note 2 to entry: a) Non-combustible test (ISO 1182).
Note 3 to entry: b) Limited combustibility test (ISO 1716).
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Note 4 to entry: Within the context of this document, "material" is understood to require the following tests:
Note 5 to entry: a) Room corner test for wall and ceiling linings (ISO/TR 9705-2).
Note 6 to entry: b) Ignitability of products when subjected to direct impingement of flame test (ISO 11925-2).
3.16
means of escape
means whereby a safe route (or routes) in the event of fire is (or are) provided for persons to travel from
any point in a building to a place of ultimate safety
3.17
multi-positional deployment
staged deployment of active fire curtain to provide initial smoke separation prior to full fire separation
3.18
property protection
application of the active fire curtain in its fire-operational c
...
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